Nagano
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Nagano Weather in September

Nagano in September sees high daytime temperatures of 24°C (75°F) and nighttime lows of 15°C (59°F). As part of the rainy season, showers are frequent and often heavy. Budget around 219 mm (8.6 in) of rainfall for the month.

Rainfall in Nagano in September

As part of the rainy season, Nagano sees around 20 days of rain in September, with an average of 219 mm (8.6 in). The rainy season here brings regular, substantial showers. It's worth being prepared for rain on most days you're out.

Temperature in Nagano in September

Expect highs of 24°C (75°F) in Nagano in September, with nights dropping to around 15°C (59°F). During September, you'll experience the summer season. This kind of day-to-night contrast is typical for this time of year. With overnight lows of 15°C (59°F), evenings can feel noticeably cooler than the daytime. An extra layer is a good idea, though the cool air makes for a good night's sleep.

Sunshine in Nagano in September

The area enjoys a balanced 142 hours of sunlight, ensuring it's neither too rainy nor too sunny.

Should you favor a climate that's both dry and comfortably warm, May typically offers the most agreeable circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.

Nagano Temperature in September

Min Temperature
15°C (59°F)
Max Temperature
24°C (75°F)
Chance of Rain
65%
Precipitation
219 mm (8.6 in)
Rainy days
20 days
Humidity
74%
Sunshine
142 hours
Percentage Sunshine

Nagano Weather by Month

Pick a month to see the average temperature, rainfall and sunshine in Nagano - and find the best time to visit.

Daily Historical Temperatures

50-year average (1976-2025)

Based on our historical records, temperatures in Nagano typically drop from around 28°C (82°F) at the start of September to approximately 22°C (72°F) by the end. Nights are pleasant, with lows typically ranging from 14°C (57°F) to 20°C (68°F).

Average temperatures in September

Daily Historical Precipitation

50-year average (1976-2025)

Average daily rainfall for each day of the month based on long-term records.

Average precipitation in September

Historical weather records for Nagano in September

Browse day-by-day weather records for Nagano spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.

Nagano historical weather extremes in September

The extremes listed below come from historical weather data collected in Nagano from 1976 through 2026.

  • The hottest September day on record in Nagano reached 36°C (97°F) (September 1, 2002).
  • The lowest daytime temperature in September was 14°C (57°F), recorded on September 27, 1980.
  • Nighttime temperatures dropped to 5°C (41°F) on September 23, 2001, marking the coldest September night on record.
  • Peak precipitation in September occurred on September 20, 2016, when 76 mm (3 in) of precipitation was measured.

Best Places in Japan in September

Find out more about the weather in Japan and which places have the best travel conditions in this month. See all of Japan in September →

perfect weather
pleasant
tolerable
unpleasant
poor

Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C (68°F) and 29°C (84°F) and not too much precipitation (less than 90 mm (3.5 in) a month).

What to Wear in Nagano in September

Pleasant temperatures in September mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Heavy rain is guaranteed, please bring a good poncho and waterproof everything! Sunglasses could come in handy during the sunnier parts of your trip.

What To Do in Nagano in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

  • Swimming
    7/10
  • Camping
    6/10

Nagano 3-Day Forecast

More climate data for Nagano

Popular in September

Where to go in September - average daytime high across popular destinations.

Bucket list

Need travel inspiration? Check out our bucket list articles and be inspired.